4 ms·

I'm fine with there just being a recognized source with wide consensus that says "we have to stay below x ppm/GTCO2 to stay below 2 degrees, and y to stay below

I'm fine with there just being a recognized source with wide consensus that says "we have to stay below x ppm/GTCO2 to stay below 2 degrees, and y to stay below 1.5, and currently we are at z." And, data on emissions rate, but those appear to be more consistent. From that you can calculate how much time we have. But so far it appears that our "scientific consensus" on those numbers range between "we have fifty years" to "we're already past that point".

skybrian 7y ago
The closest thing I've seen are graphs predicting temperature rise under different scenarios.
supercow12 7y ago
There are predictions based on various scenarios. you can see them in more detail here: https://science2017.globalchange.gov/chapter/4/ https://science2017.globalchange.gov/chapter/4/ And the various probabilities that we will stay below X degrees under the various scenarios can be found in figure 14.3 here: https://science2017.globalchange.gov/chapter/14/ https://science2017.globalchange.gov/chapter/14/ I think you are seeing an artifact of how difficult it is to explain things to non-scientists (and non-scientists misinterpreting the claims). It also tends to be difficult to find these kinds of good sources with a generic google search and no prior knowledge of the appropriate search terms. Using google scholar instead can be helpful sometimes in weeding out non-science answers for science questions.
- tunesmith 7y ago
  It's too bad, because I think people need to be able to make at least a simple version of the argument for themselves, from premises, rather than simply relying on "Scientists say..." Edit: Another example. The source you listed says the world is emitting just under 10 GtC/year. Another source I've recently seen said we are emitting 37.1 GtC/year. I've also heard 54/year but don't remember where. I mean, these numbers aren't even close.
  - skybrian 7y ago
    Hmm, I didn't see where it says 10 GtC/year, but perhaps I missed it. Could you be more specific? Looking at Figure 2.7 [1] they have "Fossil fuels and industry" at what looks like about 37, which agrees with your other source? The discrepancy in numbers might just be from measuring different things. [1] https://science2017.globalchange.gov/chapter/2/ https://science2017.globalchange.gov/chapter/2/
    - tunesmith 7y ago
      Key finding #4 in your first link: "The present-day emissions rate of nearly 10 GtC per year suggests that..."
      - skybrian 7y ago
        It seems to be the difference between carbon emissions and carbon dioxide emissions. From a different web page: "Global carbon (C) emissions from fossil fuel use were 9.795 gigatonnes (Gt) in 2014 (or 35.9 GtCO2 of carbon dioxide)." https://www.co2.earth/global-co2-emissions https://www.co2.earth/global-co2-emissions Carbon's atomic mass is about 12 and oxygen about 16. CO2 is about 27% carbon by weight.
        tunesmith 7y ago
        Oy. Thanks. I'm really getting a lesson on reading these things more closely.

skybrian 7y ago

The closest thing I've seen are graphs predicting temperature rise under different scenarios.

supercow12 7y ago

There are predictions based on various scenarios. you can see them in more detail here: https://science2017.globalchange.gov/chapter/4/ https://science2017.globalchange.gov/chapter/4/ And the various probabilities that we will stay below X degrees under the various scenarios can be found in figure 14.3 here: https://science2017.globalchange.gov/chapter/14/ https://science2017.globalchange.gov/chapter/14/ I think you are seeing an artifact of how difficult it is to explain things to non-scientists (and non-scientists misinterpreting the claims). It also tends to be difficult to find these kinds of good sources with a generic google search and no prior knowledge of the appropriate search terms. Using google scholar instead can be helpful sometimes in weeding out non-science answers for science questions.

tunesmith 7y ago
It's too bad, because I think people need to be able to make at least a simple version of the argument for themselves, from premises, rather than simply relying on "Scientists say..." Edit: Another example. The source you listed says the world is emitting just under 10 GtC/year. Another source I've recently seen said we are emitting 37.1 GtC/year. I've also heard 54/year but don't remember where. I mean, these numbers aren't even close.
- skybrian 7y ago
  Hmm, I didn't see where it says 10 GtC/year, but perhaps I missed it. Could you be more specific? Looking at Figure 2.7 [1] they have "Fossil fuels and industry" at what looks like about 37, which agrees with your other source? The discrepancy in numbers might just be from measuring different things. [1] https://science2017.globalchange.gov/chapter/2/ https://science2017.globalchange.gov/chapter/2/
  - tunesmith 7y ago
    Key finding #4 in your first link: "The present-day emissions rate of nearly 10 GtC per year suggests that..."
    - skybrian 7y ago
      It seems to be the difference between carbon emissions and carbon dioxide emissions. From a different web page: "Global carbon (C) emissions from fossil fuel use were 9.795 gigatonnes (Gt) in 2014 (or 35.9 GtCO2 of carbon dioxide)." https://www.co2.earth/global-co2-emissions https://www.co2.earth/global-co2-emissions Carbon's atomic mass is about 12 and oxygen about 16. CO2 is about 27% carbon by weight.
      - tunesmith 7y ago
        Oy. Thanks. I'm really getting a lesson on reading these things more closely.